Dapagliflozin effective against obstructive sleep apnoea hypopnea syndrome in diabetics

The sodium glucose co-transporter 2 (SGLT2) inhibitor dapagliflozin appears to have therapeutic potential in type 2 diabetes mellitus (T2DM) patients with obstructive sleep apnoea hypopnea syndrome (OSAHS), exerting beneficial effects on apnoea-hypopnea index (AHI), hypoxaemia during sleep and excessive daytime sleepiness, as shown in a study.

“If dapagliflozin can be widely confirmed to reduce OSAHS symptoms, it may be a more acceptable treatment when compared to continuous positive airway pressure (CPAP) or surgery. It has the potential to not only treat T2DM, but also play a significant role in patients with severe OSAHS, thereby reducing the development of cardiovascular or cerebrovascular illnesses, and the risk of death,” the investigators said.

In the study, 36 patients (average age, 57 years) with newly-diagnosed T2DM and OSAHS were randomized to receive dapagliflozin (n=18) or glimepiride (n=18; control) in combination with metformin (0.85 g twice daily) for 24 weeks. Dapagliflozin was initially given at 5 mg/day, with dosing increased to 10 mg/day after a week, whereas glimepiride was dosed at 2 mg/day, with a potential to double it to 4 mg/day for patients with uncontrolled glucose levels. 

Twenty-four weeks of dapagliflozin treatment led to significant reductions in triglyceride, systolic and diastolic blood pressure levels, as well as a marked increase in high-density lipoprotein cholesterol (p<0.05). These improvements were not seen in the control group. [Nutr Diabetes 2019;doi:10.1038/s41387-019-0098-5]

There were concomitant improvements observed in AHI, minimum oxygen saturation and Epworth Somnolence Scale score on dapagliflozin (p<0.05) but not on glimepiride.

Finally, patients in both treatment groups exhibited favourable changes in fasting plasma glucose, postprandial blood glucose, haemoglobin A1C, homeostasis model assessment of insulin resistance and body mass index (p<0.05) after 24 weeks of treatment, although the changes were greater with the SGLT2 inhibitor.

“The present study found that the combination of dapagliflozin and metformin not only alleviated the patient’s weight, and improved the blood glucose, blood pressure and blood lipid levels of patients with T2DM and OSAHS, but also significantly improved the patient’s ventilation and daytime sleepiness, showing that the symptoms of OSAHS patients were ameliorated,” according to the investigators.

Reports from previous studies highlighted the efficacy of metformin at inducing weight loss in T2DM and OSAHS patients but not at enhancing their ventilatory function. Therefore, dapagliflozin might have played a major role in improving ventilation in the current study population, they added. [Chest 2011;140:821A; J Sleep Med Disord 2015;2:1027]

The investigators acknowledged several study limitations, including the limited sample size, short study duration, and the failure to assess cardiovascular events and deaths as key points.

“[L]arge prospective randomized clinical trials are required to evaluate the effectiveness and safety of dapagliflozin in treating OSAHS, determine the additional health benefits that can be measured in comparison with other treatments, and determine whether other SGLT2 inhibitors, such as empagliflozin and canagliflozin, can also improve the symptoms and prognosis of OSAHS patients,” they said.